Related Experiment Video
Updated: Apr 15, 2026

Preparation of Free-Surface Hyperbolic Water Vortices
Published on: July 28, 2023
Hydrodynamic modelling of free water-surface constructed storm water wetlands using a finite volume technique
Mohammad Zounemat-Kermani1, Miklas Scholz, Mohammad-Mahdi Tondar
1a Department of Water Engineering , Shahid Bahonar University of Kerman , Kerman , Iran.
Abstract:
One of the key factors in designing free water-surface constructed wetlands (FWS CW) is the hydraulic efficiency (λ), which depends primarily on the retention time of the polluted storm water. Increasing the hydraulic retention time (HRT) at various flow levels will increase λ of the overall constructed wetland (CW). The effects of characteristic geometric features that increase HRT were explored through the use of a two-dimensional depth-average hydrodynamic model. This numerical model was developed to solve the equations of continuity and motions on an unstructured triangular mesh using the Galerkin finite volume formulation and equations of the k-ε turbulence model. Eighty-nine diverse forms of artificial FWS CW with 11 different aspect ratios were numerically simulated and subsequently analysed for four scenarios: rectangular CW, modified rectangular CW with rounded edges, different inlet/outlet configurations of CW, and surface and submerged obstructions in front of the inlet part of the CW. Results from the simulations showed that increasing the aspect ratio has a direct influence on the enhancement of λ in all cases. However, the aspect ratio should be at least 9 in order to achieve an appropriate rate for λ in rectangular CW. Modified rounded rectangular CW improved λ by up to 23%, which allowed for the selection of a reduced aspect ratio. Simulation results showed that CW with low aspect ratios benefited from obstructions and optimized inlet/outlet configurations in terms of improved HRT.
Related Concept Videos
Conservation of Mass in Moving, Nondeforming Control Volume
In the context of a detention basin, the conservation of mass states that the total mass of water entering the basin must equal the mass leaving the basin plus any accumulation of...
Design Example: Creating a Hydraulic Model of a Dam Spillway
Typical Model Studies
Rapidly Varying Flow
Modeling and Similitude
Design Example: Analyzing Capacity Contours for Flood Risk Assessment

